Dunn J C, Tompkins R G, Yarmush M L
Department of Surgery, Massachusetts General Hospital, Harvard Medical School, Boston 02114.
J Cell Biol. 1992 Feb;116(4):1043-53. doi: 10.1083/jcb.116.4.1043.
The influence of extracellular matrix configuration on the tissue-specific function of cultured hepatocytes was investigated. Adult rat hepatocytes sandwiched between two layers of collagen gel were compared to cells cultured on a single layer of collagen gel for differences in the total RNA content, the level of albumin-specific mRNA, the rate of albumin gene transcription, and the rate of albumin mRNA translation. Adult hepatocytes in the sandwich system maintained the level of albumin mRNA similar to that found in the normal liver for at least six weeks, whereas the level of albumin mRNA declined rapidly in the single gel system. After one week of culture, hepatocytes in the single gel system could be induced to recover the high level of albumin mRNA and albumin production when a second layer of collagen gel was overlaid at that time. Furthermore, sandwiched hepatocytes maintained significantly higher transcriptional activity compared to cells in the single gel system. In addition to transcriptional control, the ultimate rate of albumin production was shown to depend on the rate of translation, which increased with culture time and reached a plateau in one to two weeks. This increase in translational activity over time in culture was observed in both the sandwich and the single gel systems and, thus, appeared to be independent of the configuration of extracellular matrix.
研究了细胞外基质构型对培养肝细胞组织特异性功能的影响。将夹在两层胶原凝胶之间的成年大鼠肝细胞与单层胶原凝胶上培养的细胞进行比较，观察其总RNA含量、白蛋白特异性mRNA水平、白蛋白基因转录速率和白蛋白mRNA翻译速率的差异。夹心系统中的成年肝细胞至少六周内维持与正常肝脏中相似的白蛋白mRNA水平，而单层凝胶系统中白蛋白mRNA水平迅速下降。培养一周后，单层凝胶系统中的肝细胞在此时覆盖第二层胶原凝胶时可被诱导恢复高水平的白蛋白mRNA和白蛋白产生。此外，与单层凝胶系统中的细胞相比，夹心肝细胞维持着显著更高的转录活性。除了转录控制外，白蛋白产生的最终速率还取决于翻译速率，翻译速率随培养时间增加，并在一到两周内达到稳定水平。在夹心和单层凝胶系统中均观察到培养过程中翻译活性随时间的这种增加，因此，这似乎与细胞外基质的构型无关。
